diff --git a/web_strategy_studio/frontend/src/test/setup.ts b/web_strategy_studio/frontend/src/test/setup.ts
new file mode 100644
index 0000000..b67bfcf
--- /dev/null
+++ b/web_strategy_studio/frontend/src/test/setup.ts
@@ -0,0 +1,11 @@
+import { vi } from "vitest";
+
+if (!("ResizeObserver" in globalThis)) {
+  class ResizeObserver {
+    observe(_target: Element, _options?: ResizeObserverOptions) {}
+    unobserve(_target: Element) {}
+    disconnect() {}
+  }
+
+  vi.stubGlobal("ResizeObserver", ResizeObserver);
+}
diff --git a/web_strategy_studio/frontend/vite.config.ts b/web_strategy_studio/frontend/vite.config.ts
index eaa0031..f98df2a 100644
--- a/web_strategy_studio/frontend/vite.config.ts
+++ b/web_strategy_studio/frontend/vite.config.ts
@@ -16,6 +16,7 @@ export default defineConfig({
   },
   test: {
     environment: "jsdom",
+    setupFiles: "./src/test/setup.ts",
     passWithNoTests: true,
   },
 });